Pocantico Hills, Westchester County, New York, USA June 9, 2017 Size: ~7mm
This is a very slender ant-like bee with white scopal hairs and large jaws. The bee is a little more than 7 mm in length. Its jaws are very long -- more than ¾ the length of its compound eyes.
Is this Chelostoma philadelphi? There is mock orange in the immediate vicinity -- although this bee was visiting chamomile.